“Addition of sildenafil to yohimbine significantly enhanced the effect of the latter on intromission frequency, intercopulatory interval and the number of ejaculations per session.”
“ Sildenafil may enhance the central effects of yohimbine on erection; it amplifies the effect of yohimbine on male copulatory performance but not on sexual motivation.”
“Yohimbine alone failed to potentiate erectile responses but yohimbine (1 μmol kg−1) significantly potentiated the effect of sildenafil 1–10 μmol kg−1 and 1 mmol kg−1, 1 and 5 min after injection.”